An air conditioned environment is important to personal comfort and even health. The most common air conditioning units controlled by individuals are the home air conditioner, usually a central electric unit or electric window air unit, and the automobile air conditioner.
As is well known, air conditioning a room or house electrically becomes quite expensive. Many people, particularly elder people on a fixed budget, can not afford to run the air conditioning. As a result, many elderly people must suffer through the summer heat at risk to their very health.
Even if one is financially secure to run a home air conditioning unit, and pay for the extra gasoline necessary to run an automobile air conditioning unit, those units are by their very nature only effective at the home or when in the car. A conventional air conditioning system, usually requiring a source of power, a compressor, an evaporator, a fan, and a condenser, is dearly impractical for portable use.